Materiały źródłowe

• #1 Mitral Valve Prolapse – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK470288/

  Mitral valve prolapse (MVP) is the primary myxomatous degeneration of 1 or both mitral valve leaflets. Myxomatous degeneration may involve valve leaflet abnormalities, chordae tendineae weakening, and elongation, mitral annular dilatation or thickened leaflet tissue, elongated chordae, mitral annular enlargement leading to segmental mitral leaflet prolapse. Other pathophysiological changes include fibroelastic deficiency characterized by thin, translucent, and smooth leaflets or deficiency in elastin, proteoglycan, and collagen with connective tissue deficiency. […] Endothelium disruption leads to complications such as infectious endocarditis and thromboembolism. Most MVP individuals have minimal mitral valve structure derangement, which is not clinically significant. There is usually a gross redundancy of the mitral valve leaflets, which fails the coaptation of the leaflets during systole, leading to mitral insufficiency. Over time, the patient develops mitral annual dilatation, resulting in further worsening of the mitral insufficiency. Fortunately, most patients have minor derangements in the leaflets and are asymptomatic.

• #2 Imaging of Mitral Valve Prolapse: What Can We Learn from Imaging about the Mechanism of the Disease?

  https://www.mdpi.com/2308-3425/2/3/165

  Mitral valve prolapse (MVP) is the most common mitral valve disorder affecting 2%–3% of the general population. Two histological forms for the disease exist: Myxomatous degeneration and fibroelastic disease. Pathological evidence suggests the disease is not confined solely to the valve tissue, and accumulation of proteoglycans and fibrotic tissue can be seen in the adjacent myocardium of MVP patients. MVP is diagnosed by demonstrating valve tissue passing the annular line into the left atrium during systole. […] Pathological processes in MVP are not limited to the valves only. Pathological studies of MVP patients with sudden death or death from other causes have shown proteoglycan depositions similar to the deposition within the leaflet also in the myocardial tissue, fibrous endocardial plaque depositions, and non-specific interstitial fibrosis. These depositions are thought to play a role in the increased tendency of MVP patients for cardiac arrhythmia, sudden death and chest pain.

• #3 Mitral valve prolapse – Symptoms & causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/mitral-valve-prolapse/symptoms-causes/syc-20355446

  Mitral valve prolapse is a type of heart valve disease that affects the valve between the left heart chambers. The flaps (leaflets) of the mitral valve are floppy. They bulge backward (prolapse) like a parachute into the heart’s left upper chamber as the heart squeezes (contracts). […] In mitral valve prolapse, one or both of the mitral valve leaflets have extra tissue or stretch more than usual. The leaflets can bulge backward (prolapse) like a parachute into the left upper heart chamber (left atrium) each time the heart contracts to pump blood. […] The bulging may keep the valve from closing tightly. If blood leaks backward through the valve, the condition is called mitral valve regurgitation.

• #4 Epidemiology and Pathophysiology of Mitral Valve Prolapse: New Insights into Disease Progression, Genetics, and Molecular Basis

  https://pmc.ncbi.nlm.nih.gov/articles/PMC4052751/

  MVP is characterized by progressive increases in the area and length of the MV tissue, and typically progresses with a natural history spanning decades, causing leaflets to thicken anatomically and prolapse superiorly into the left atrium beyond the mitral annulus in systole, leading to MR. Histologically, the mitral leaflets in MVP are characterized by myxomatous degeneration. A detailed explanation of myxomatous changes requires an understanding of the histology and the development of the normal MV. […] Myxomatous degeneration is characterized by the expansion of the middle spongiosa layer of the valve (due to an accumulation of proteoglycans), structural alterations of collagen in all components of the leaflet, and by structurally abnormal chordae. Dysregulation of ECM components plays a key role in mediating these changes. In MVP, the VICs acquire properties of activated myofibroblasts characterized by the expression of vimentin and alpha-smooth muscle actin, but not SM1 or SM2 (markers of differentiated smooth muscle cells). Activated myofibroblasts are responsible for increased concentrations of various proteolytic enzymes, including matrix metalloproteinases, which degrade collagen and elastin at a rate exceeding the rate of production seen in quiescent VICs.

• #5 Mitral Valve Prolapse: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/155494-overview

  Mitral valve prolapse (MVP) is characterized primarily by myxomatous degeneration of the mitral valve leaflets. In younger populations, there is gross redundancy of both the anterior and posterior leaflets and chordal apparatus. This is the extreme form of myxomatous degeneration, known as Barlow syndrome. In older populations, however, MVP is characterized by fibroelastic deficiency, sometimes with superimposed chordal rupture due to a lack of connective tissue support. […] These anatomic abnormalities result in malcoaptation of mitral valve leaflets during systole, resulting in regurgitation. Mitral annular dilatation may also develop over time, resulting in further progression of mitral regurgitation (MR). Acute severe MR results in congestive heart failure symptoms without left ventricular dilatation. Conversely, chronic or progressively severe MR can lead to ventricular dilatation and dysfunction, neurohormonal activation, and heart failure. Elevation in left atrial pressures can result in left atrial enlargement, atrial fibrillation, pulmonary congestion, and pulmonary hypertension.

• #6 Mitral valve prolapse – Wikipedia

  https://en.wikipedia.org/wiki/Mitral_valve_prolapse

  Mitral valve prolapse (MVP) is a valvular heart disease characterized by the displacement of an abnormally thickened mitral valve leaflet into the left atrium during systole. […] Patients with classic mitral valve prolapse have excess connective tissue that thickens the spongiosa and separates collagen bundles in the fibrosa. This is due to an excess of dermatan sulfate, a glycosaminoglycan. This weakens the leaflets and adjacent tissue, resulting in increased leaflet area and elongation of the chordae tendineae. Elongation of the chordae tendineae often causes rupture, commonly to the chordae attached to the posterior leaflet. Advanced lesions also commonly involving the posterior leaflet lead to leaflet folding, inversion, and displacement toward the left atrium. […] MVP is understood histologically, as a form of myxomatous degeneration, which is a type of connective tissue changes. In MVP, the spongiosa layer of the mitral valve leaflets undergoes proliferation, and the cells in this layer multiply and expand. This proliferation is associated with the accumulation of deposits of mucopolysaccharide, which have a high water content, which leads to an increase in the thickness and redundancy (excess tissue) of the leaflets of the mitral valve.

• #7 12.4 Etiology and mechanism of mitral regurgitation | 123sonography

  https://123sonography.com/ebook/etiology-and-mechanism-mitral-regurgitation

  In mitral valve prolapse the valve protrudes beyond the mitral annular plane into the left atrium. Prolapse may affect portions of a leaflet (i.e. scallop), only one leaflet, or the entire valve. The term „mitral valve prolapse” in the strict sense is a functional definition. It may occur in the presence of various diseases such as endocarditis, „fibroelastic deficiency”, and even rheumatic heart disease. It may also occur when the annulus is small or squeezed – as in the presence of excessive right heart dilatation. […] When we refer to mitral valve prolapse we usually mean a specific pathology of the mitral valve, referred to as degenerative myxomatous mitral valve prolapse, and also known as Barlow’s disease, floppy mitral valve, or classic mitral valve prolapse. Myxomatous mitral valve prolapse is characterized by an abnormal tissue composition with mucopolysaccharide accumulation, and changes in collagen and elastic fibers. This leads to functional impairment and affects the competence of the valve. In addition, it weakens the tissue and may lead to chordal rupture (see section on flail leaflet).

• #8 Epidemiology and Pathophysiology of Mitral Valve Prolapse: New Insights into Disease Progression, Genetics, and Molecular Basis

  https://pmc.ncbi.nlm.nih.gov/articles/PMC4052751/

  MVP is characterized by progressive increases in the area and length of the MV tissue, and typically progresses with a natural history spanning decades, causing leaflets to thicken anatomically and prolapse superiorly into the left atrium beyond the mitral annulus in systole, leading to MR. Histologically, the mitral leaflets in MVP are characterized by myxomatous degeneration. A detailed explanation of myxomatous changes requires an understanding of the histology and the development of the normal MV. […] Myxomatous degeneration is characterized by the expansion of the middle spongiosa layer of the valve (due to an accumulation of proteoglycans), structural alterations of collagen in all components of the leaflet, and by structurally abnormal chordae. Dysregulation of ECM components plays a key role in mediating these changes. In MVP, the VICs acquire properties of activated myofibroblasts characterized by the expression of vimentin and alpha-smooth muscle actin, but not SM1 or SM2 (markers of differentiated smooth muscle cells). Activated myofibroblasts are responsible for increased concentrations of various proteolytic enzymes, including matrix metalloproteinases, which degrade collagen and elastin at a rate exceeding the rate of production seen in quiescent VICs.

• #9 Epidemiology and Pathophysiology of Mitral Valve Prolapse: New Insights into Disease Progression, Genetics, and Molecular Basis

  https://pmc.ncbi.nlm.nih.gov/articles/PMC4052751/

  Some clues to the various signaling pathways involved in abnormal valve biology in MVP can be gleamed from our understanding of normal heart valve development. Early septation of the cardiac tube into distinct chambers is achieved through regional swellings of the extracellular matrix, known as cardiac cushions, which form the primordial valves. Reciprocal signaling between the endocardial and myocardial cell layers in the cardiac cushion (mediated in part by members of the TGF-} family) induces a transformation of the endothelial cells (VECs) into interstitial or mesenchymal cells (VICs). This transformation is also known as endothelial to mesenchymal transition or EMT. […] TGF- up-regulation appears to have a pivotal role among various biological pathways in the pathogenesis of primary or non-syndromic MVP. Specifically, TGF- is known to activate VICs towards a pathologic synthetic phenotype, as shown both in animal models and in human in-vitro studies.

• #10

  https://www.jci.org/articles/view/23701

  In a study reported in this issue of the JCI, Ng et al. tested the hypothesis that the fibrillin-1TGF- pathway is implicated in the pathogenesis of MVP in a murine model of Marfan syndrome. […] Most interestingly, the mitral valve phenotype was rescued by TGF-neutralizing antibodies, which confirms a causal relationship between TGF- dysregulation and this abnormal mitral valve. […] The finding that TGF- dysregulation in the connective tissue plays an important role in the development of prolapse in Marfan syndrome raises the question as to whether this cytokine may play a role in other forms of prolapse, including sporadic MVP. […] However, a great deal of study remains necessary before the pathogenic mechanisms underlying idiopathic MVP and its relationship to more generalized forms of connective tissue disease are clarified.

• #11

  https://www.jci.org/articles/view/23701

  In a study reported in this issue of the JCI, Ng et al. tested the hypothesis that the fibrillin-1TGF- pathway is implicated in the pathogenesis of MVP in a murine model of Marfan syndrome. […] Most interestingly, the mitral valve phenotype was rescued by TGF-neutralizing antibodies, which confirms a causal relationship between TGF- dysregulation and this abnormal mitral valve. […] The finding that TGF- dysregulation in the connective tissue plays an important role in the development of prolapse in Marfan syndrome raises the question as to whether this cytokine may play a role in other forms of prolapse, including sporadic MVP. […] However, a great deal of study remains necessary before the pathogenic mechanisms underlying idiopathic MVP and its relationship to more generalized forms of connective tissue disease are clarified.

• #12 Mitral valve prolapse – Wikipedia

  https://en.wikipedia.org/wiki/Mitral_valve_prolapse

  Research has shown an association between MVP and primary cilia defects. Studies have identified mutations in the Zinc finger protein DZIP1 gene which regulates ciliogenesis; the same problem was found in mice who also developed MVP with this gene. It was found that primary cilia loss during development results in progressive myxomatous degeneration and profound mitral valve pathology.

• #13 Imaging of Mitral Valve Prolapse: What Can We Learn from Imaging about the Mechanism of the Disease?

  https://www.mdpi.com/2308-3425/2/3/165

  Mitral valve prolapse (MVP) is the most common mitral valve disorder affecting 2%–3% of the general population. Two histological forms for the disease exist: Myxomatous degeneration and fibroelastic disease. Pathological evidence suggests the disease is not confined solely to the valve tissue, and accumulation of proteoglycans and fibrotic tissue can be seen in the adjacent myocardium of MVP patients. MVP is diagnosed by demonstrating valve tissue passing the annular line into the left atrium during systole. […] Pathological processes in MVP are not limited to the valves only. Pathological studies of MVP patients with sudden death or death from other causes have shown proteoglycan depositions similar to the deposition within the leaflet also in the myocardial tissue, fibrous endocardial plaque depositions, and non-specific interstitial fibrosis. These depositions are thought to play a role in the increased tendency of MVP patients for cardiac arrhythmia, sudden death and chest pain.

• #14 Mitral valve prolapse: an underestimated cause of sudden cardiac death—a current review of the literature – Spartalis – Journal of Thoracic Disease

  https://jtd.amegroups.org/article/view/17315/html

  Mitral valve prolapse (MVP) is characterized by a systolic displacement of one or both mitral leaflets below the mitral annulus plane into the left atrium (LA). […] Different pathological processes can cause prolapse of the mitral valve, such as rheumatic heart disease, endocarditis, Marfan syndrome, and ischemic heart disease, but degenerative MVP attributes especially to a specific gamut of primary lesions. These are the fibroelastic deficiency (FED) and Barlow syndrome. FED is a fibrillin deficiency that causes chordal rupture. The annular size is normal, and the mitral valve leaflets are thinned. Patients with Barlow syndrome are typically young individuals. Myxomatous degeneration may lead to mitral annulus calcification and dilatation with thickened leaflets. […] The presence of a dilated LV in severe MR may imply a period of LV remodeling. In acute primary MR, afterload can decline in the beginning because of the altered route for ejection. With LV volume overloading though, the rather thin-walled LV may enlarge and become hypertrophic. Therefore, the afterload in chronic compensated MR will be normal and increased in chronic decompensated MR. Remodeling of the LV can allow MR to be tolerated with no significant symptomatology by enhancing the stroke volume. Development of heart failure and probably cardiac death can manifest rapidly, due to the presence of myocardial dysfunction and sympathetic activation. LV remodeling has been correlated with the manifestation of ventricular arrhythmias.

• #15 Mitral Valve Prolapse: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/155494-overview

  Mitral valve prolapse (MVP) is characterized primarily by myxomatous degeneration of the mitral valve leaflets. In younger populations, there is gross redundancy of both the anterior and posterior leaflets and chordal apparatus. This is the extreme form of myxomatous degeneration, known as Barlow syndrome. In older populations, however, MVP is characterized by fibroelastic deficiency, sometimes with superimposed chordal rupture due to a lack of connective tissue support. […] These anatomic abnormalities result in malcoaptation of mitral valve leaflets during systole, resulting in regurgitation. Mitral annular dilatation may also develop over time, resulting in further progression of mitral regurgitation (MR). Acute severe MR results in congestive heart failure symptoms without left ventricular dilatation. Conversely, chronic or progressively severe MR can lead to ventricular dilatation and dysfunction, neurohormonal activation, and heart failure. Elevation in left atrial pressures can result in left atrial enlargement, atrial fibrillation, pulmonary congestion, and pulmonary hypertension.

• #16 Mitral Valve Prolapse – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK470288/

  Mitral valve prolapse (MVP) is the primary myxomatous degeneration of 1 or both mitral valve leaflets. Myxomatous degeneration may involve valve leaflet abnormalities, chordae tendineae weakening, and elongation, mitral annular dilatation or thickened leaflet tissue, elongated chordae, mitral annular enlargement leading to segmental mitral leaflet prolapse. Other pathophysiological changes include fibroelastic deficiency characterized by thin, translucent, and smooth leaflets or deficiency in elastin, proteoglycan, and collagen with connective tissue deficiency. […] Endothelium disruption leads to complications such as infectious endocarditis and thromboembolism. Most MVP individuals have minimal mitral valve structure derangement, which is not clinically significant. There is usually a gross redundancy of the mitral valve leaflets, which fails the coaptation of the leaflets during systole, leading to mitral insufficiency. Over time, the patient develops mitral annual dilatation, resulting in further worsening of the mitral insufficiency. Fortunately, most patients have minor derangements in the leaflets and are asymptomatic.

• #17 Mitral Valve Prolapse (MVP) – Cardiovascular Disorders – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/cardiovascular-disorders/valvular-disorders/mitral-valve-prolapse-mvp

  Mitral valve prolapse is most often caused by idiopathic myxomatous degeneration of the mitral valve and chordae tendineae. […] In myxomatous degeneration, the fibrous collagen layer of the valve thins and mucoid (myxomatous) material accumulates. The chordae become longer and thinner and the valve leaflets enlarge and become rubbery. These changes result in floppy valve leaflets that can balloon back (prolapse) into the left atrium when the left ventricle contracts. […] Mitral annular disjunction (MAD) is partial detachment of the mitral annulus from the ventricular myocardium, allowing for hypermobility of the mitral valve. MAD is strongly associated with mitral valve prolapse and ventricular arrhythmias. Identification of MAD can alter the surgical technique used for mitral valve repair.

• #18 Mitral valve prolapse – Wikipedia

  https://en.wikipedia.org/wiki/Mitral_valve_prolapse

  Mitral valve prolapse (MVP) is a valvular heart disease characterized by the displacement of an abnormally thickened mitral valve leaflet into the left atrium during systole. […] Patients with classic mitral valve prolapse have excess connective tissue that thickens the spongiosa and separates collagen bundles in the fibrosa. This is due to an excess of dermatan sulfate, a glycosaminoglycan. This weakens the leaflets and adjacent tissue, resulting in increased leaflet area and elongation of the chordae tendineae. Elongation of the chordae tendineae often causes rupture, commonly to the chordae attached to the posterior leaflet. Advanced lesions also commonly involving the posterior leaflet lead to leaflet folding, inversion, and displacement toward the left atrium. […] MVP is understood histologically, as a form of myxomatous degeneration, which is a type of connective tissue changes. In MVP, the spongiosa layer of the mitral valve leaflets undergoes proliferation, and the cells in this layer multiply and expand. This proliferation is associated with the accumulation of deposits of mucopolysaccharide, which have a high water content, which leads to an increase in the thickness and redundancy (excess tissue) of the leaflets of the mitral valve.

• #19 Mitral Valve Prolapse: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/155494-overview

  Mitral valve prolapse (MVP) is characterized primarily by myxomatous degeneration of the mitral valve leaflets. In younger populations, there is gross redundancy of both the anterior and posterior leaflets and chordal apparatus. This is the extreme form of myxomatous degeneration, known as Barlow syndrome. In older populations, however, MVP is characterized by fibroelastic deficiency, sometimes with superimposed chordal rupture due to a lack of connective tissue support. […] These anatomic abnormalities result in malcoaptation of mitral valve leaflets during systole, resulting in regurgitation. Mitral annular dilatation may also develop over time, resulting in further progression of mitral regurgitation (MR). Acute severe MR results in congestive heart failure symptoms without left ventricular dilatation. Conversely, chronic or progressively severe MR can lead to ventricular dilatation and dysfunction, neurohormonal activation, and heart failure. Elevation in left atrial pressures can result in left atrial enlargement, atrial fibrillation, pulmonary congestion, and pulmonary hypertension.

• #20 Mitral Valve Prolapse (MVP) – Cardiovascular Disorders – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/cardiovascular-disorders/valvular-disorders/mitral-valve-prolapse-mvp

  Mitral valve prolapse is most often caused by idiopathic myxomatous degeneration of the mitral valve and chordae tendineae. […] In myxomatous degeneration, the fibrous collagen layer of the valve thins and mucoid (myxomatous) material accumulates. The chordae become longer and thinner and the valve leaflets enlarge and become rubbery. These changes result in floppy valve leaflets that can balloon back (prolapse) into the left atrium when the left ventricle contracts. […] Mitral annular disjunction (MAD) is partial detachment of the mitral annulus from the ventricular myocardium, allowing for hypermobility of the mitral valve. MAD is strongly associated with mitral valve prolapse and ventricular arrhythmias. Identification of MAD can alter the surgical technique used for mitral valve repair.

• #21

  https://omim.org/entry/157700

  Mitral valve prolapse (MVP) has a prevalence of approximately 2 to 3% in the general population. It is characterized by fibromyxomatous changes in mitral leaflet tissue, with upward displacement of 1 or both leaflets into the left atrium during systole; MVP is diagnosed when the movement of the mitral leaflets exceeds 2 mm. […] Delling and Vasan (2014) reviewed the epidemiology and pathophysiology of MVP, with discussion of disease progression, genetics, and molecular basis. […] In functional terms, mitral valve prolapse results from a valve-ventricle mismatch. Hutchins et al. (1986) pointed out that the fundamental fault is often not in the valve leaflets, but in the mitral annulus which is stretched with resulting disjunction between the atrium and ventricle. […] On the basis of linkage studies, Henney et al. (1989) and Wordsworth et al. (1989) excluded the involvement of the COL1A1 (120150), COL1A2 (120160), COL3A1 (120180), and COL5A2 (120190) in the pathogenesis of familial mitral valve prolapse. […] By systematic echocardiographic screening of the first-degree relatives of 17 patients who underwent mitral valve repair for myxomatous mitral valve prolapse, Disse et al. (1999) identified 4 pedigrees showing autosomal dominant inheritance.

• #22 Mitral valve prolapse – Symptoms & causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/mitral-valve-prolapse/symptoms-causes/syc-20355446

  Mitral valve prolapse is a type of heart valve disease that affects the valve between the left heart chambers. The flaps (leaflets) of the mitral valve are floppy. They bulge backward (prolapse) like a parachute into the heart’s left upper chamber as the heart squeezes (contracts). […] In mitral valve prolapse, one or both of the mitral valve leaflets have extra tissue or stretch more than usual. The leaflets can bulge backward (prolapse) like a parachute into the left upper heart chamber (left atrium) each time the heart contracts to pump blood. […] The bulging may keep the valve from closing tightly. If blood leaks backward through the valve, the condition is called mitral valve regurgitation.

• #23 Mitral Valve Prolapse: Symptoms & Treatment

  https://my.clevelandclinic.org/health/diseases/17241-mitral-valve-prolapse

  Mitral valve prolapse causes your valve leaflets and chordae tendineae to be too stretchy, resulting in blood leaks backward from your left ventricle into your left atrium. […] Valve tissue weakness (myxomatous degeneration) causes mitral valve prolapse. Its not always clear what causes this tissue weakness. In some cases, families may pass it down to their biological children. Researchers have linked mitral valve prolapse with several genes, including FLNA, DCHS1, DZIP1 and PLD1. […] Some connective tissue disorders may cause myxomatous degeneration. These include Marfan syndrome, Ehlers-Danlos syndrome and Loeys-Dietz syndrome. […] The main complication of MVP is mitral regurgitation. This means blood leaks the wrong way through your valve from your left ventricle into your left atrium. MVP is one of the most common causes of mitral regurgitation. If the leak is severe enough, you may need surgery or a procedure to help your valve work as it should. […] Mitral valve prolapse (floppy valve syndrome) is a type of myxomatous valve disease. This means the tissue of your mitral valve leaflets is abnormally stretchy, which makes them floppy.

• #24 Mitral valve disease: clinical features focusing on auscultatory findings including auscultation of mitral valve prolapse

  https://www.escardio.org/Journals/E-Journal-of-Cardiology-Practice/Volume-16/Mitral-valve-disease-clinical-features-focusing-on-auscultatory-findings-including-auscultation-of-mitral-valve-prolapse

  Dynamic auscultation is quite useful to establish the diagnosis of MVP. The mitral valve starts to prolapse when the LV systolic volume reaches a specific point below which the valve leaflets cannot coapt. At this point the click occurs and MR and hence murmur starts. Anything that decreases the left ventricular volume such as decreased venous return, tachycardia, increased myocardial contractility or reduced afterload will cause the mitral valve leaflets to prolapse earlier in systole, and systolic click and murmur will move towards the first sound and the murmur will become longer. On the other hand, when LV volume is increased because of increased venous return, increased afterload, decreased myocardial contractility and bradycardia, the onset of click and murmur will be delayed. […] The change in intensity of murmur after a premature beat helps in differentiating MVP murmur from that of hypertrophic cardiomyopathy (HCM). The intensity and duration of HCM murmur increases after a premature ventricular beat compared to MVP murmur where the intensity decreases or remains unchanged.

• #25 Mitral valve prolapse – Symptoms & causes – Mayo Clinic

  https://www.mayoclinic.org/diseases-conditions/mitral-valve-prolapse/symptoms-causes/syc-20355446

  Mitral valve prolapse is a type of heart valve disease that affects the valve between the left heart chambers. The flaps (leaflets) of the mitral valve are floppy. They bulge backward (prolapse) like a parachute into the heart’s left upper chamber as the heart squeezes (contracts). […] In mitral valve prolapse, one or both of the mitral valve leaflets have extra tissue or stretch more than usual. The leaflets can bulge backward (prolapse) like a parachute into the left upper heart chamber (left atrium) each time the heart contracts to pump blood. […] The bulging may keep the valve from closing tightly. If blood leaks backward through the valve, the condition is called mitral valve regurgitation.

• #26 Mitral Valve Prolapse (MVP) – Cardiovascular Disorders – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/cardiovascular-disorders/valvular-disorders/mitral-valve-prolapse-mvp

  Mitral regurgitation (MR) due to mitral valve prolapse may occur in patients with apparently normal mitral valve leaflets (ie, nonmyxomatous) due to ischemic papillary muscle dysfunction or rheumatic chordal rupture. […] Mitral valve prolapse does not usually require treatment. […] Prognosis is usually benign unless MR develops, in which case there is increased risk of heart failure, atrial fibrillation, stroke, and infective endocarditis.

• #27 Mitral valve disease: clinical features focusing on auscultatory findings including auscultation of mitral valve prolapse

  https://www.escardio.org/Journals/E-Journal-of-Cardiology-Practice/Volume-16/Mitral-valve-disease-clinical-features-focusing-on-auscultatory-findings-including-auscultation-of-mitral-valve-prolapse

  Mitral valve prolapse (MVP) is the leading cause of significant MR in developed countries. MVP, or degenerative mitral valve disease as it is sometimes called in a broader sense, is defined by a spectrum of mitral valve lesions involving one or more components of the mitral valve apparatus. It can vary from simple chordal rupture with prolapse of an isolated segment of the posterior leaflet (P2) in an otherwise normal valve to multi-segment prolapse affecting one or both leaflets in a valve with significantly excess tissue and a larger annulus. […] The characteristic auscultatory feature of MVP is a mid-systolic click, a high-pitched sound. It results from sudden tensing of the mitral valve apparatus as the leaflets prolapse into the left atrium in systole. Multiple clicks can be heard as different parts of the mitral leaflets prolapse at different times of systole. The loudness and timing of the clicks can vary according to left ventricular volume and contractility. Compared to aortic ejection click which occurs with the beginning of the carotid pulse upstroke, the clicks of MVP happen after the beginning of the upstroke. The clicks are often but not always followed by a mid or late systolic murmur. The duration of the murmur usually corresponds with the severity of MR. When the murmur is restricted only to the later part of the systole, the MR is not severe but, as the MR progresses, the systolic murmur becomes holosystolic.

• #28 Mitral valve disease: clinical features focusing on auscultatory findings including auscultation of mitral valve prolapse

  https://www.escardio.org/Journals/E-Journal-of-Cardiology-Practice/Volume-16/Mitral-valve-disease-clinical-features-focusing-on-auscultatory-findings-including-auscultation-of-mitral-valve-prolapse

  Dynamic auscultation is quite useful to establish the diagnosis of MVP. The mitral valve starts to prolapse when the LV systolic volume reaches a specific point below which the valve leaflets cannot coapt. At this point the click occurs and MR and hence murmur starts. Anything that decreases the left ventricular volume such as decreased venous return, tachycardia, increased myocardial contractility or reduced afterload will cause the mitral valve leaflets to prolapse earlier in systole, and systolic click and murmur will move towards the first sound and the murmur will become longer. On the other hand, when LV volume is increased because of increased venous return, increased afterload, decreased myocardial contractility and bradycardia, the onset of click and murmur will be delayed. […] The change in intensity of murmur after a premature beat helps in differentiating MVP murmur from that of hypertrophic cardiomyopathy (HCM). The intensity and duration of HCM murmur increases after a premature ventricular beat compared to MVP murmur where the intensity decreases or remains unchanged.

• #29

  https://journals.lww.com/mamc/fulltext/2015/01030/mechanisms_and_pathophysiology_of_mitral_valve.6.aspx

  The precise mechanism of functional mitral regurgitation remains unclear; the factors described above can be grouped as those causing: (1) Abnormally increased tension on the leaflets caused by displacement of the papillary muscles or annular dilatation, restricting leaflet motion, and those causing (2) decreased global LV systolic function, decreasing the transmitral pressure force acting to close the mitral leaflets. […] The dynamic nature of the regurgitant orifice which decreases as the LV contracts further complicates elucidation of the mechanisms of MR. […] In the presence of MR, during systole, LV empties into the low-pressure high compliance LA as well as into the high-pressure and high-resistance systemic circulation. […] The pressure-volume relationship in presence of MR is shown in Figure 4, the shape of the pressure-volume loop is abnormal, the area of the loop and the end-diastolic volume is grossly increased, there is absence of isovolumic contraction phase and the LV volume starts decreasing as soon as the LV starts to contract.

• #30 Mitral Valve Prolapse: Practice Essentials, Background, Pathophysiology

  https://emedicine.medscape.com/article/155494-overview

  Mitral valve prolapse (MVP) is characterized primarily by myxomatous degeneration of the mitral valve leaflets. In younger populations, there is gross redundancy of both the anterior and posterior leaflets and chordal apparatus. This is the extreme form of myxomatous degeneration, known as Barlow syndrome. In older populations, however, MVP is characterized by fibroelastic deficiency, sometimes with superimposed chordal rupture due to a lack of connective tissue support. […] These anatomic abnormalities result in malcoaptation of mitral valve leaflets during systole, resulting in regurgitation. Mitral annular dilatation may also develop over time, resulting in further progression of mitral regurgitation (MR). Acute severe MR results in congestive heart failure symptoms without left ventricular dilatation. Conversely, chronic or progressively severe MR can lead to ventricular dilatation and dysfunction, neurohormonal activation, and heart failure. Elevation in left atrial pressures can result in left atrial enlargement, atrial fibrillation, pulmonary congestion, and pulmonary hypertension.

• #31 Mitral valve prolapse: an underestimated cause of sudden cardiac death—a current review of the literature – Spartalis – Journal of Thoracic Disease

  https://jtd.amegroups.org/article/view/17315/html

  Mitral valve prolapse (MVP) is characterized by a systolic displacement of one or both mitral leaflets below the mitral annulus plane into the left atrium (LA). […] Different pathological processes can cause prolapse of the mitral valve, such as rheumatic heart disease, endocarditis, Marfan syndrome, and ischemic heart disease, but degenerative MVP attributes especially to a specific gamut of primary lesions. These are the fibroelastic deficiency (FED) and Barlow syndrome. FED is a fibrillin deficiency that causes chordal rupture. The annular size is normal, and the mitral valve leaflets are thinned. Patients with Barlow syndrome are typically young individuals. Myxomatous degeneration may lead to mitral annulus calcification and dilatation with thickened leaflets. […] The presence of a dilated LV in severe MR may imply a period of LV remodeling. In acute primary MR, afterload can decline in the beginning because of the altered route for ejection. With LV volume overloading though, the rather thin-walled LV may enlarge and become hypertrophic. Therefore, the afterload in chronic compensated MR will be normal and increased in chronic decompensated MR. Remodeling of the LV can allow MR to be tolerated with no significant symptomatology by enhancing the stroke volume. Development of heart failure and probably cardiac death can manifest rapidly, due to the presence of myocardial dysfunction and sympathetic activation. LV remodeling has been correlated with the manifestation of ventricular arrhythmias.

• #32

  https://journals.lww.com/mamc/fulltext/2015/01030/mechanisms_and_pathophysiology_of_mitral_valve.6.aspx

  The precise mechanism of functional mitral regurgitation remains unclear; the factors described above can be grouped as those causing: (1) Abnormally increased tension on the leaflets caused by displacement of the papillary muscles or annular dilatation, restricting leaflet motion, and those causing (2) decreased global LV systolic function, decreasing the transmitral pressure force acting to close the mitral leaflets. […] The dynamic nature of the regurgitant orifice which decreases as the LV contracts further complicates elucidation of the mechanisms of MR. […] In the presence of MR, during systole, LV empties into the low-pressure high compliance LA as well as into the high-pressure and high-resistance systemic circulation. […] The pressure-volume relationship in presence of MR is shown in Figure 4, the shape of the pressure-volume loop is abnormal, the area of the loop and the end-diastolic volume is grossly increased, there is absence of isovolumic contraction phase and the LV volume starts decreasing as soon as the LV starts to contract.

• #33 Mitral valve prolapse: an underestimated cause of sudden cardiac death—a current review of the literature – Spartalis – Journal of Thoracic Disease

  https://jtd.amegroups.org/article/view/17315/html

  Mitral valve prolapse (MVP) is characterized by a systolic displacement of one or both mitral leaflets below the mitral annulus plane into the left atrium (LA). […] Different pathological processes can cause prolapse of the mitral valve, such as rheumatic heart disease, endocarditis, Marfan syndrome, and ischemic heart disease, but degenerative MVP attributes especially to a specific gamut of primary lesions. These are the fibroelastic deficiency (FED) and Barlow syndrome. FED is a fibrillin deficiency that causes chordal rupture. The annular size is normal, and the mitral valve leaflets are thinned. Patients with Barlow syndrome are typically young individuals. Myxomatous degeneration may lead to mitral annulus calcification and dilatation with thickened leaflets. […] The presence of a dilated LV in severe MR may imply a period of LV remodeling. In acute primary MR, afterload can decline in the beginning because of the altered route for ejection. With LV volume overloading though, the rather thin-walled LV may enlarge and become hypertrophic. Therefore, the afterload in chronic compensated MR will be normal and increased in chronic decompensated MR. Remodeling of the LV can allow MR to be tolerated with no significant symptomatology by enhancing the stroke volume. Development of heart failure and probably cardiac death can manifest rapidly, due to the presence of myocardial dysfunction and sympathetic activation. LV remodeling has been correlated with the manifestation of ventricular arrhythmias.

• #34 12.4 Etiology and mechanism of mitral regurgitation | 123sonography

  https://123sonography.com/ebook/124-etiology-and-mechanism-mitral-regurgitation

  Myxomatous mitral valve prolapse is a progressive disease with a hereditary component (autosomal dominant). Approximately 30-50% of first-degree relatives also have mitral valve prolapse. It is often diagnosed in young adults, more commonly in women, and is frequently associated with tricuspid valve prolapse (40-50%). The aortic valve is involved in 10-20%. There is also an association between mitral valve prolapse and skeletal abnormalities of the chest. […] It should be noted that prolapse is just one morphological component of this disease. Other findings include thickened leaflets and chordae, excessive tissue, and rocking motion of the annulus. Thus, the diagnosis of myxomatous mitral valve prolapse should not only be based on the presence of a prolapse but also on other findings. Mitral valve prolapse may affect the entire valve, only one leaflet, or specific segments or scallops. The echocardiographic investigation should encompass the entire valve. […] In mitral valve prolapse you should fully describe: a) the morphology of the valve (thickening), b) the extent and location of prolapse, c) the degree, mechanism and origin of mitral regurgitation, and d) coexistence of chordal rupture.

• #35 Genetics and pathophysiology of mitral valve prolapse

  https://ouci.dntb.gov.ua/en/works/lRmGDgj4/

  Mitral valve prolapse (MVP) is a common condition affecting 2–3% of the general population, and the most complex form of valve pathology, with a complication rate up to 10–15% per year in advanced stages. […] MVP can occur as part of syndromic conditions such as Marfan syndrome, but the most common form is non-syndromic, isolated or familial. […] Although a specific X-linked form of MVP was initially identified, autosomal dominant inheritance appears to be the primary mode of transmission. […] MVP can be stratified into myxomatous degeneration (Barlow), fibroelastic deficiency, and Filamin A-related MVP. […] While FED is still considered a degenerative disease associated with aging, myxomatous MVP and FlnA-MVP are recognized as familial pathologies. […] Deciphering genetic defects associated to MVP is still a work in progress; although FLNA, DCHS1, and DZIP1 have been identified as causative genes in myxomatous forms of MVP thanks to familial approaches, they explain only a small proportion of MVP. […] Furthermore, a potential genetic link between MVP and ventricular arrhythmia or a specific type of cardiomyopathy is considered. […] Corroborated by genetic data and animal models, the main pathophysiological pathways of MVP are briefly addressed.

• #36

  https://link.springer.com/article/10.1007/s12170-008-0082-4

  Mitral valve prolapse (MVP) is a common cardiac disorder that exhibits a strong hereditary component. […] MVP loci have been mapped to chromosomes 11, 13, and 16 by studying large families with multiple affected members, and mutations in the filamin A gene have been shown to cause familial cardiac valvular dystrophy, an X-linked form of MVP. […] Determination of the genetic basis of MVP is important because the disease often manifests clinically in the fifth or sixth decade of life through presentation as a severe cardiac event. […] TGF-beta-dependent pathogenesis of mitral valve prolapse in a mouse model of Marfan syndrome.

• #37 Genetics and pathophysiology of mitral valve prolapse

  https://ouci.dntb.gov.ua/en/works/lRmGDgj4/

  Mitral valve prolapse (MVP) is a common condition affecting 2–3% of the general population, and the most complex form of valve pathology, with a complication rate up to 10–15% per year in advanced stages. […] MVP can occur as part of syndromic conditions such as Marfan syndrome, but the most common form is non-syndromic, isolated or familial. […] Although a specific X-linked form of MVP was initially identified, autosomal dominant inheritance appears to be the primary mode of transmission. […] MVP can be stratified into myxomatous degeneration (Barlow), fibroelastic deficiency, and Filamin A-related MVP. […] While FED is still considered a degenerative disease associated with aging, myxomatous MVP and FlnA-MVP are recognized as familial pathologies. […] Deciphering genetic defects associated to MVP is still a work in progress; although FLNA, DCHS1, and DZIP1 have been identified as causative genes in myxomatous forms of MVP thanks to familial approaches, they explain only a small proportion of MVP. […] Furthermore, a potential genetic link between MVP and ventricular arrhythmia or a specific type of cardiomyopathy is considered. […] Corroborated by genetic data and animal models, the main pathophysiological pathways of MVP are briefly addressed.

• #38 Mitral Valve Prolapse: Symptoms & Treatment

  https://my.clevelandclinic.org/health/diseases/17241-mitral-valve-prolapse

  Mitral valve prolapse causes your valve leaflets and chordae tendineae to be too stretchy, resulting in blood leaks backward from your left ventricle into your left atrium. […] Valve tissue weakness (myxomatous degeneration) causes mitral valve prolapse. Its not always clear what causes this tissue weakness. In some cases, families may pass it down to their biological children. Researchers have linked mitral valve prolapse with several genes, including FLNA, DCHS1, DZIP1 and PLD1. […] Some connective tissue disorders may cause myxomatous degeneration. These include Marfan syndrome, Ehlers-Danlos syndrome and Loeys-Dietz syndrome. […] The main complication of MVP is mitral regurgitation. This means blood leaks the wrong way through your valve from your left ventricle into your left atrium. MVP is one of the most common causes of mitral regurgitation. If the leak is severe enough, you may need surgery or a procedure to help your valve work as it should. […] Mitral valve prolapse (floppy valve syndrome) is a type of myxomatous valve disease. This means the tissue of your mitral valve leaflets is abnormally stretchy, which makes them floppy.

• #39

  https://link.springer.com/article/10.1007/s12170-008-0082-4

  Mitral valve prolapse (MVP) is a common cardiac disorder that exhibits a strong hereditary component. […] MVP loci have been mapped to chromosomes 11, 13, and 16 by studying large families with multiple affected members, and mutations in the filamin A gene have been shown to cause familial cardiac valvular dystrophy, an X-linked form of MVP. […] Determination of the genetic basis of MVP is important because the disease often manifests clinically in the fifth or sixth decade of life through presentation as a severe cardiac event. […] TGF-beta-dependent pathogenesis of mitral valve prolapse in a mouse model of Marfan syndrome.

• #40 Genetics and pathophysiology of mitral valve prolapse

  https://ouci.dntb.gov.ua/en/works/lRmGDgj4/

  Mitral valve prolapse (MVP) is a common condition affecting 2–3% of the general population, and the most complex form of valve pathology, with a complication rate up to 10–15% per year in advanced stages. […] MVP can occur as part of syndromic conditions such as Marfan syndrome, but the most common form is non-syndromic, isolated or familial. […] Although a specific X-linked form of MVP was initially identified, autosomal dominant inheritance appears to be the primary mode of transmission. […] MVP can be stratified into myxomatous degeneration (Barlow), fibroelastic deficiency, and Filamin A-related MVP. […] While FED is still considered a degenerative disease associated with aging, myxomatous MVP and FlnA-MVP are recognized as familial pathologies. […] Deciphering genetic defects associated to MVP is still a work in progress; although FLNA, DCHS1, and DZIP1 have been identified as causative genes in myxomatous forms of MVP thanks to familial approaches, they explain only a small proportion of MVP. […] Furthermore, a potential genetic link between MVP and ventricular arrhythmia or a specific type of cardiomyopathy is considered. […] Corroborated by genetic data and animal models, the main pathophysiological pathways of MVP are briefly addressed.

• #41 Arrhythmogenic Mitral Valve Prolapse | AER Journal

  https://www.aerjournal.com/articles/arrhythmogenic-mitral-valve-prolapse?language_content_entity=en

  Mitral valve prolapse (MVP) is a common condition present in 13% of the population. The arrhythmogenic mechanism is related to fibrotic changes in the papillary muscles caused by the prolapsing valve. On the microscopic level, MVP is characterised by marked proliferation of the spongiosa, a glycosaminoglycan and proteoglycan-rich middle layer contained within a spongy elastin network. This causes interruption of the fibrosa, the underlying, collagen-rich lower layer located towards the ventricular side of the valve. Secondary effects include fibrotic changes on the mitral valve leaflets, thinning and elongation of the chordae tendinae, which is also caused by accumulation of glycosaminoglycans and ventricular friction lesions. There is some evidence the MVP itself may be the cause of the papillary and peripapillary fibrotic changes. The pathological systolic shortening and deformation may exert excessive traction on the papillary muscle, therefore inducing fibrotic change. These fibrotic changes, friction lesions and myocardial stretching may give rise to ventricular arrhythmias either through re-entry or triggered activity. Furthermore, there is evidence of increased sympathetic activity, coupled with decreased vagal activity and elevated catecholamine levels in MVP patients with a high ventricular arrhythmic load. To summarise, the pathogenesis of arrhythmia in MVP is best explained when we consider the myocardial hypertrophy and fibrosis as the substrate with the mechanical stretch being the trigger of the arrhythmia.

• #42 Mitral valve prolapse: an underestimated cause of sudden cardiac death—a current review of the literature – Spartalis – Journal of Thoracic Disease

  https://jtd.amegroups.org/article/view/17315/html

  Valve leaflet dumping in diastole or traction on papillary muscles could serve as a mechanical trigger for ventricular arrhythmias. Redundant and thickened leaflets have been identified as a risk factor for SCA in MVP. Endocardial friction lesions in the left ventricle may serve as a focus of arrhythmias as well. Some pathology studies have indicated that a cardiomyopathic process accompanying MVP or the autonomic nervous system dysfunction may play a role. […] The genetic substrate has also been linked with MVP and SCD. Missov et al. reported a case of SCD due to a novel disease, causing mutation in the SCN5A gene encoding the cardiac sodium channels in a patient with myxomatous mitral valve disease and flail posterior leaflet. […] The struggle against SCD must combine primary and secondary prevention methods. There are cardiac causes of SCD that either remain unidentified or, if found, do not still have specific guidelines for management. We should be aware that most MVP patients die suddenly at rest or during sleep at home.

• #43 Arrhythmogenic Mitral Valve Prolapse | AER Journal

  https://www.aerjournal.com/articles/arrhythmogenic-mitral-valve-prolapse?language_content_entity=en

  Mitral valve prolapse (MVP) is a common condition present in 13% of the population. The arrhythmogenic mechanism is related to fibrotic changes in the papillary muscles caused by the prolapsing valve. On the microscopic level, MVP is characterised by marked proliferation of the spongiosa, a glycosaminoglycan and proteoglycan-rich middle layer contained within a spongy elastin network. This causes interruption of the fibrosa, the underlying, collagen-rich lower layer located towards the ventricular side of the valve. Secondary effects include fibrotic changes on the mitral valve leaflets, thinning and elongation of the chordae tendinae, which is also caused by accumulation of glycosaminoglycans and ventricular friction lesions. There is some evidence the MVP itself may be the cause of the papillary and peripapillary fibrotic changes. The pathological systolic shortening and deformation may exert excessive traction on the papillary muscle, therefore inducing fibrotic change. These fibrotic changes, friction lesions and myocardial stretching may give rise to ventricular arrhythmias either through re-entry or triggered activity. Furthermore, there is evidence of increased sympathetic activity, coupled with decreased vagal activity and elevated catecholamine levels in MVP patients with a high ventricular arrhythmic load. To summarise, the pathogenesis of arrhythmia in MVP is best explained when we consider the myocardial hypertrophy and fibrosis as the substrate with the mechanical stretch being the trigger of the arrhythmia.

• #44 Risk Stratification in Arrhythmogenic Mitral Valve Prolapse | AER Journal

  https://www.aerjournal.com/articles/arrhythmogenic-mitral-valve-prolapse-can-we-risk-stratify-and-prevent-sudden-cardiac-death?language_content_entity=en

  The early identification and treatment of malignant MVP is made difficult due to the limited data available and a lack of evidence-based guidelines. […] There is renewed interest regarding the spatially and/or time-altered myocardial electrical conductions that cause malignant VAs secondary to a prolapsing MV, with a view to a greater understanding of its epidemiology, mechanism, diagnosis and link to public health in the broader context of SCD. […] Accurate risk stratification of MVP with a likelihood of malignant VA is an important clinical and public health issue, which would allow for more precise and targeted management and the consideration of appropriate ICD therapy for the primary and secondary prevention of SCD in this cohort. […] The most widely supported and substantiated mechanistic link between MVP and VA (malignant MVP) is considered to be an interaction between an acute abnormal mechanical stretch of the PM during systolic leaflet prolapse causing afterdepolarisation-triggered PVCs, and progressive hypertrophy with fibrosis most often localised in the basal/mid-inferolateral LV or PM secondary to repeated traction of the prolapsing leaflets.

• #45 Arrhythmogenic Mitral Valve Prolapse | AER Journal

  https://www.aerjournal.com/articles/arrhythmogenic-mitral-valve-prolapse?language_content_entity=en

  Mitral valve prolapse (MVP) is a common condition present in 13% of the population. The arrhythmogenic mechanism is related to fibrotic changes in the papillary muscles caused by the prolapsing valve. On the microscopic level, MVP is characterised by marked proliferation of the spongiosa, a glycosaminoglycan and proteoglycan-rich middle layer contained within a spongy elastin network. This causes interruption of the fibrosa, the underlying, collagen-rich lower layer located towards the ventricular side of the valve. Secondary effects include fibrotic changes on the mitral valve leaflets, thinning and elongation of the chordae tendinae, which is also caused by accumulation of glycosaminoglycans and ventricular friction lesions. There is some evidence the MVP itself may be the cause of the papillary and peripapillary fibrotic changes. The pathological systolic shortening and deformation may exert excessive traction on the papillary muscle, therefore inducing fibrotic change. These fibrotic changes, friction lesions and myocardial stretching may give rise to ventricular arrhythmias either through re-entry or triggered activity. Furthermore, there is evidence of increased sympathetic activity, coupled with decreased vagal activity and elevated catecholamine levels in MVP patients with a high ventricular arrhythmic load. To summarise, the pathogenesis of arrhythmia in MVP is best explained when we consider the myocardial hypertrophy and fibrosis as the substrate with the mechanical stretch being the trigger of the arrhythmia.

• #46 Risk Stratification in Arrhythmogenic Mitral Valve Prolapse | AER Journal

  https://www.aerjournal.com/articles/arrhythmogenic-mitral-valve-prolapse-can-we-risk-stratify-and-prevent-sudden-cardiac-death?language_content_entity=en

  The early identification and treatment of malignant MVP is made difficult due to the limited data available and a lack of evidence-based guidelines. […] There is renewed interest regarding the spatially and/or time-altered myocardial electrical conductions that cause malignant VAs secondary to a prolapsing MV, with a view to a greater understanding of its epidemiology, mechanism, diagnosis and link to public health in the broader context of SCD. […] Accurate risk stratification of MVP with a likelihood of malignant VA is an important clinical and public health issue, which would allow for more precise and targeted management and the consideration of appropriate ICD therapy for the primary and secondary prevention of SCD in this cohort. […] The most widely supported and substantiated mechanistic link between MVP and VA (malignant MVP) is considered to be an interaction between an acute abnormal mechanical stretch of the PM during systolic leaflet prolapse causing afterdepolarisation-triggered PVCs, and progressive hypertrophy with fibrosis most often localised in the basal/mid-inferolateral LV or PM secondary to repeated traction of the prolapsing leaflets.

• #47 Mitral valve prolapse: an underestimated cause of sudden cardiac death—a current review of the literature – Spartalis – Journal of Thoracic Disease

  https://jtd.amegroups.org/article/view/17315/html

  Valve leaflet dumping in diastole or traction on papillary muscles could serve as a mechanical trigger for ventricular arrhythmias. Redundant and thickened leaflets have been identified as a risk factor for SCA in MVP. Endocardial friction lesions in the left ventricle may serve as a focus of arrhythmias as well. Some pathology studies have indicated that a cardiomyopathic process accompanying MVP or the autonomic nervous system dysfunction may play a role. […] The genetic substrate has also been linked with MVP and SCD. Missov et al. reported a case of SCD due to a novel disease, causing mutation in the SCN5A gene encoding the cardiac sodium channels in a patient with myxomatous mitral valve disease and flail posterior leaflet. […] The struggle against SCD must combine primary and secondary prevention methods. There are cardiac causes of SCD that either remain unidentified or, if found, do not still have specific guidelines for management. We should be aware that most MVP patients die suddenly at rest or during sleep at home.

• #48 Risk Stratification in Arrhythmogenic Mitral Valve Prolapse | AER Journal

  https://www.aerjournal.com/articles/arrhythmogenic-mitral-valve-prolapse-can-we-risk-stratify-and-prevent-sudden-cardiac-death?language_content_entity=en

  The early identification and treatment of malignant MVP is made difficult due to the limited data available and a lack of evidence-based guidelines. […] There is renewed interest regarding the spatially and/or time-altered myocardial electrical conductions that cause malignant VAs secondary to a prolapsing MV, with a view to a greater understanding of its epidemiology, mechanism, diagnosis and link to public health in the broader context of SCD. […] Accurate risk stratification of MVP with a likelihood of malignant VA is an important clinical and public health issue, which would allow for more precise and targeted management and the consideration of appropriate ICD therapy for the primary and secondary prevention of SCD in this cohort. […] The most widely supported and substantiated mechanistic link between MVP and VA (malignant MVP) is considered to be an interaction between an acute abnormal mechanical stretch of the PM during systolic leaflet prolapse causing afterdepolarisation-triggered PVCs, and progressive hypertrophy with fibrosis most often localised in the basal/mid-inferolateral LV or PM secondary to repeated traction of the prolapsing leaflets.

• #49 Pathophysiology of Ischaemic Mitral Valve Prolapse: A Review of the Evidence and Implications for Surgical Treatment – European Medical Journal

  https://www.emjreviews.com/cardiology/article/pathophysiology-of-ischaemic-mitral-valve-prolapse-a-review-of-the-evidence-and-implications-for-surgical-treatment/

  Ischaemic mitral prolapse (IMP) is a pathologic entity encountered in about one-third of patients undergoing surgery for ischaemic mitral regurgitation. IMP is generally the result of a papillary muscle injury consequent to myocardial infarction, but the recent literature is progressively unveiling a more complex pathogenesis. The mechanisms underlying its development are the impairment of one or more components of the mitral apparatus, which comprises the annulus, chordae tendineae, papillary muscle, and left ventricular wall. […] IMP is not only a disorder of valvular function but also entails coexistent aspects of a geometric disturbance of the mitral valve configuration and of the left ventricular function and dimension. A correct understanding of all these aspects is crucial to guide and tailor the correct therapeutic strategy to be adopted. Localisation of prolapse and anatomic features of the prolapsed leaflets and the subvalvular apparatus should be carefully evaluated as also constituting the major determinants defining patient outcomes.

• #50 Ischemic mitral valve prolapse – Nappi – Journal of Thoracic Disease

  https://jtd.amegroups.org/article/view/11217/html

  Ischemic mitral prolapse (IMP) is generally the result of a papillary muscle injury consequent to myocardial, but the recent literature is progressively unveiling a more complex pathogenesis. […] The mechanisms underlying its development regards the impairment of one or more components of the mitral apparatus, which comprises the annulus, the chordae tendineae, the papillary muscle and the left ventricular wall. […] The consequence of IMP is not only related to a disorder of valvular function, but also implicates coexistent futures of a geometric disturbance of the mitral valve configuration and of the left ventricular function and dimension. […] The pathophysiology of ischemic mitral valve prolapse is divided in: (I) pattern of necrosis of a separate commissural head involving rupture of the harborage of the commissural chord; (II) pattern of necrosis of a single head papillary muscle subdivided in multiple heads evolving in partial rupture; (III) pattern of necrosis of a fenestrated papillary muscle with detachment of its main insertion supporting an incomplete rupture.

• #51 Pathophysiology of Ischaemic Mitral Valve Prolapse: A Review of the Evidence and Implications for Surgical Treatment – European Medical Journal

  https://www.emjreviews.com/cardiology/article/pathophysiology-of-ischaemic-mitral-valve-prolapse-a-review-of-the-evidence-and-implications-for-surgical-treatment/

  Ischaemic mitral prolapse (IMP) is a pathologic entity encountered in about one-third of patients undergoing surgery for ischaemic mitral regurgitation. IMP is generally the result of a papillary muscle injury consequent to myocardial infarction, but the recent literature is progressively unveiling a more complex pathogenesis. The mechanisms underlying its development are the impairment of one or more components of the mitral apparatus, which comprises the annulus, chordae tendineae, papillary muscle, and left ventricular wall. […] IMP is not only a disorder of valvular function but also entails coexistent aspects of a geometric disturbance of the mitral valve configuration and of the left ventricular function and dimension. A correct understanding of all these aspects is crucial to guide and tailor the correct therapeutic strategy to be adopted. Localisation of prolapse and anatomic features of the prolapsed leaflets and the subvalvular apparatus should be carefully evaluated as also constituting the major determinants defining patient outcomes.

• #52 Ischemic mitral valve prolapse – Nappi – Journal of Thoracic Disease

  https://jtd.amegroups.org/article/view/11217/html

  Ischemic mitral prolapse (IMP) is generally the result of a papillary muscle injury consequent to myocardial, but the recent literature is progressively unveiling a more complex pathogenesis. […] The mechanisms underlying its development regards the impairment of one or more components of the mitral apparatus, which comprises the annulus, the chordae tendineae, the papillary muscle and the left ventricular wall. […] The consequence of IMP is not only related to a disorder of valvular function, but also implicates coexistent futures of a geometric disturbance of the mitral valve configuration and of the left ventricular function and dimension. […] The pathophysiology of ischemic mitral valve prolapse is divided in: (I) pattern of necrosis of a separate commissural head involving rupture of the harborage of the commissural chord; (II) pattern of necrosis of a single head papillary muscle subdivided in multiple heads evolving in partial rupture; (III) pattern of necrosis of a fenestrated papillary muscle with detachment of its main insertion supporting an incomplete rupture.

• #53 Pathophysiology of Ischaemic Mitral Valve Prolapse: A Review of the Evidence and Implications for Surgical Treatment – European Medical Journal

  https://www.emjreviews.com/cardiology/article/pathophysiology-of-ischaemic-mitral-valve-prolapse-a-review-of-the-evidence-and-implications-for-surgical-treatment/

  Although much of the original focus is centred on the abnormal restriction of the valve leaflets, the disease is significantly more complex. […] The mechanisms of ischaemic mitral valve prolapse result in: a) necrosis of a separate commissural head inserted close to the annulus, with rupture of the anchorage of the commissural chord; b) necrosis of a single head PM subdivided in multiple heads with partial rupture; or c) necrosis of a fenestrated PM, with detachment of its main insertion favouring an incomplete rupture. […] The morphology of the posterior PM, which is the usual site of ischaemic injury, is more complex than the anterior PM, and its subdivision into several heads is very frequent. IMP is frequently caused by a partial PM rupture or elongation limited to a single head. Alternatively, prolapse can be favoured by an incomplete detachment of a head due to a rupture of its main insertion with the body while remaining fixed to the ventricle via muscular bridges (incomplete PM rupture).

• #54 Pathophysiology of Ischaemic Mitral Valve Prolapse: A Review of the Evidence and Implications for Surgical Treatment – European Medical Journal

  https://www.emjreviews.com/cardiology/article/pathophysiology-of-ischaemic-mitral-valve-prolapse-a-review-of-the-evidence-and-implications-for-surgical-treatment/

  The IMP involves an imbalance between tethering forces and closing forces in the valvular and subvalvular apparatus. […] Accumulating evidence suggests that the presence of primary lesion or dysfunction of PM leads to prolapse in 86.4% of IMR patients. […] The presence of IMP is regarded as an indication to perform surgery, as it underlies more than a simple annular dilation, which can be mainly addressed by myocardial revascularisation and interrupting the ventricular remodelling process. Conversely, the appearance of IMP indicates an alteration of more than one of the components of the mitral apparatus and valve configuration (annulus, PM, chordae, LV geometry) and therefore requires more careful attention in the operative work-up.

• #55 Ischemic mitral valve prolapse – Nappi – Journal of Thoracic Disease

  https://jtd.amegroups.org/article/view/11217/html

  The complexity of injury has an effect on the imbalance between tethering forces and closing forces of the valvular and subvalvular apparatus. […] The presence of IMP is regarded as an indication to perform surgery. Indeed, it underlies more than a simple annular dilation, which can be normally addressed by myocardial revascularization interrupting the ventricular remodeling process. Conversely, IMP indicates an alteration of more than one of the components of the mitral apparatus and valve configuration (annulus, PM, chordae, LV geometry) and therefore requires a more meticulous attitude during the operative work-up.

• #56 A Modified Echocardiographic Classification of Mitral Valve Regurgitation Mechanism: The Role of Three-dimensional Echocardiography

  https://e-jcvi.org/search.php?where=aview&id=10.4250/jcvi.2019.27.e29&code=3059JCVI&vmode=PUBREADER

  Compared to 2D imaging, 3D echocardiography obviates the need to mentally reconstruct the MV in three dimensions from multiple 2D images to understand the underlying MV anatomy. […] The main role for 3D echocardiography in this subtype is assessment of the MV area, and this has become the reference method of classifying MV stenosis because it facilitates imaging of the true narrowest opening of the MV orifice. […] In types III-B and III-C, there is systolic restriction with one or more tethered leaflets. […] The closure and position of mitral leaflets are determined by the balance between two forces acting on them: the closing forces generated by the LV systolic contraction, which effectively closes the valve, and the tethering forces, which restrain the leaflets to prevent leaflet prolapse.

• #57 Mitral valve prolapse-widening views onto the myocardium by cardiovascular magnetic resonance | Society for Cardiovascular Magnetic Resonance

  https://scmr.org/cases-of-scmr/number-11-15/

  Pathophysiologically, MV prolapse is regarded as an intrinsic abnormality of the MV and its subvalvular apparatus, characterized by displacement of MV leaflets from the annular plane, causing various degrees of regurgitation during systole. […] Our observations indicate a possible novel mechanism outlined by differential (basal-apical) myocardial deformation in inferior and inferolateral walls leading to apical displacement of the MV annular plane, relative displacement of the posterior leaflet below the plane of the anterior leaflet and consequently mitral regurgitation. […] We reveal such mechanism in two independent clinical cases of known MV prolapse, potentially summing up to a novel observation warranting further mechanistic studies by assessment of myocardial deformation.

• #58 Out-of-hospital cardiac arrest in a mitral valve prolapse young male patient with acute mitral regurgitation due to cordal rupture. A case with a literature review – itjem

  https://www.itjem.org/2017/10/17/out-of-hospital-cardiac-arrest-in-a-mitral-valve-prolapse-young-male-patient-with-acute-mitral-regurgitation-due-to-cordal-rupture-a-case-with-a-literature-review/

  Furthermore, some studies have suggested that ventricular arrhythmias may be more frequent in MVP when mitral regurgitation is present. […] Additionally, it has been proposed that a subset of young patients with isolated MVP and SCD could actually have less mitral regurgitation. […] The arrhythmic substrate in this setting of patients was also recently investigated by Basso and colleagues, who found that in patients who experienced sudden cardiac death with MVP was present fibrosis in the papillary muscles of adjacent free wall and infero-basal wall, as demonstrated by late gadolinium-enhancement on magnetic resonance study. […] Moreover, the degree of MVP and leaflets thickness was found to be related with QT dispersion, providing also a mechanical correlation for electrical disturbances in this subset of patients.

• #59 Mitral valve prolapse-widening views onto the myocardium by cardiovascular magnetic resonance | Society for Cardiovascular Magnetic Resonance

  https://scmr.org/cases-of-scmr/number-11-15/

  Pathophysiologically, MV prolapse is regarded as an intrinsic abnormality of the MV and its subvalvular apparatus, characterized by displacement of MV leaflets from the annular plane, causing various degrees of regurgitation during systole. […] Our observations indicate a possible novel mechanism outlined by differential (basal-apical) myocardial deformation in inferior and inferolateral walls leading to apical displacement of the MV annular plane, relative displacement of the posterior leaflet below the plane of the anterior leaflet and consequently mitral regurgitation. […] We reveal such mechanism in two independent clinical cases of known MV prolapse, potentially summing up to a novel observation warranting further mechanistic studies by assessment of myocardial deformation.

• #60 12.4 Etiology and mechanism of mitral regurgitation | 123sonography

  https://123sonography.com/ebook/124-etiology-and-mechanism-mitral-regurgitation

  Myxomatous mitral valve prolapse is a progressive disease with a hereditary component (autosomal dominant). Approximately 30-50% of first-degree relatives also have mitral valve prolapse. It is often diagnosed in young adults, more commonly in women, and is frequently associated with tricuspid valve prolapse (40-50%). The aortic valve is involved in 10-20%. There is also an association between mitral valve prolapse and skeletal abnormalities of the chest. […] It should be noted that prolapse is just one morphological component of this disease. Other findings include thickened leaflets and chordae, excessive tissue, and rocking motion of the annulus. Thus, the diagnosis of myxomatous mitral valve prolapse should not only be based on the presence of a prolapse but also on other findings. Mitral valve prolapse may affect the entire valve, only one leaflet, or specific segments or scallops. The echocardiographic investigation should encompass the entire valve. […] In mitral valve prolapse you should fully describe: a) the morphology of the valve (thickening), b) the extent and location of prolapse, c) the degree, mechanism and origin of mitral regurgitation, and d) coexistence of chordal rupture.

• #61 Mitral Valve Prolapse – StatPearls – NCBI Bookshelf

  https://www.ncbi.nlm.nih.gov/books/NBK470288/

  Mitral valve prolapse (MVP) is the primary myxomatous degeneration of 1 or both mitral valve leaflets. Myxomatous degeneration may involve valve leaflet abnormalities, chordae tendineae weakening, and elongation, mitral annular dilatation or thickened leaflet tissue, elongated chordae, mitral annular enlargement leading to segmental mitral leaflet prolapse. Other pathophysiological changes include fibroelastic deficiency characterized by thin, translucent, and smooth leaflets or deficiency in elastin, proteoglycan, and collagen with connective tissue deficiency. […] Endothelium disruption leads to complications such as infectious endocarditis and thromboembolism. Most MVP individuals have minimal mitral valve structure derangement, which is not clinically significant. There is usually a gross redundancy of the mitral valve leaflets, which fails the coaptation of the leaflets during systole, leading to mitral insufficiency. Over time, the patient develops mitral annual dilatation, resulting in further worsening of the mitral insufficiency. Fortunately, most patients have minor derangements in the leaflets and are asymptomatic.

• #62 Epidemiology and Pathophysiology of Mitral Valve Prolapse: New Insights into Disease Progression, Genetics, and Molecular Basis

  https://pmc.ncbi.nlm.nih.gov/articles/PMC4052751/

  MVP is characterized by progressive increases in the area and length of the MV tissue, and typically progresses with a natural history spanning decades, causing leaflets to thicken anatomically and prolapse superiorly into the left atrium beyond the mitral annulus in systole, leading to MR. Histologically, the mitral leaflets in MVP are characterized by myxomatous degeneration. A detailed explanation of myxomatous changes requires an understanding of the histology and the development of the normal MV. […] Myxomatous degeneration is characterized by the expansion of the middle spongiosa layer of the valve (due to an accumulation of proteoglycans), structural alterations of collagen in all components of the leaflet, and by structurally abnormal chordae. Dysregulation of ECM components plays a key role in mediating these changes. In MVP, the VICs acquire properties of activated myofibroblasts characterized by the expression of vimentin and alpha-smooth muscle actin, but not SM1 or SM2 (markers of differentiated smooth muscle cells). Activated myofibroblasts are responsible for increased concentrations of various proteolytic enzymes, including matrix metalloproteinases, which degrade collagen and elastin at a rate exceeding the rate of production seen in quiescent VICs.

• #63 Mitral Valve Prolapse (MVP) – Cardiovascular Disorders – Merck Manual Professional Edition

  https://www.merckmanuals.com/professional/cardiovascular-disorders/valvular-disorders/mitral-valve-prolapse-mvp

  Mitral valve prolapse is most often caused by idiopathic myxomatous degeneration of the mitral valve and chordae tendineae. […] In myxomatous degeneration, the fibrous collagen layer of the valve thins and mucoid (myxomatous) material accumulates. The chordae become longer and thinner and the valve leaflets enlarge and become rubbery. These changes result in floppy valve leaflets that can balloon back (prolapse) into the left atrium when the left ventricle contracts. […] Mitral annular disjunction (MAD) is partial detachment of the mitral annulus from the ventricular myocardium, allowing for hypermobility of the mitral valve. MAD is strongly associated with mitral valve prolapse and ventricular arrhythmias. Identification of MAD can alter the surgical technique used for mitral valve repair.

• #64 Improving Care for Mitral Valve Prolapse | UCSF Cardiology

  https://ucsfhealthcardiology.ucsf.edu/giving/research-and-clinical-highlights/improving-care-mitral-valve-prolapse

  Mitral valve prolapse can also cause a more serious problem. The leaflets are connected by thin tendons to the papillary muscles at the base of the heart. Floppy leaflets can pull on the papillary muscles, and that repeated tugging can cause fibrosis, or scarring. Scar tissue does not conduct electrical signals, and can interfere with the hearts ability to beat properly. Some patients may develop ventricular arrhythmias irregular heart rhythms arising from the ventricles, which are the main pumping chambers of the heart. […] By understanding the mechanism, we could develop medical therapies that halt progression, she said. Thats really where the future is.

• #65 Prognostic Significance of Mitral Valve Prolapse

  https://www.longdom.org/open-access/prognostic-significance-of-mitral-valve-prolapse-93085.html

  A frequent valvular condition called Mitral Valve Prolapse (MVP) has been linked to heart failure, ventricular arrhythmias, sudden cardiac death, and Mitral Regurgitation (MR). […] Regarding the underlying processes of LV remodeling in the setting of non-syndromic MVP, a number of potential ideas have been put up too far, but the precise pathophysiological explanation is still difficult. […] In general, volume overload associated with severe MR is thought to be the primary factor causing LV dilatation in MVP. […] Given the connection between MVP and cardiac fibrosis, a concurrent cardiomyopathy is another possibility. […] The precise pathophysiological mechanism causing LV remodeling in MVP is still unknown, and the underlying processes are only partially understood. […] The prolapse volume, concurrent cardiomyopathy caused by myocardial fibrosis and ventricular arrhythmias, hereditary susceptibility, and other recent theories have all been put forth to explain this abnormal LV remodeling in MVP. […] An increasing amount of studies suggests that non-syndromic MVP is also a hereditary disorder with autosomal dominant or Xlinked inheritance, in addition to syndromic types of MVP (like Marfan syndrome).

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